Electric oil pressure gauge



.lune 16, 1942. R. cLAsoN 2,286,717

ELECTRIC OIL PRESSURE GAUGE Filed Dec. 4. 1940 Snuentor Patented June 16, 1942 UNITED STATES PATENT OFFICE nacraxc on. nessuna GAUGE Begur Claaon. Flint, meh., assigner to General Motors Corporation, Mich., a corporation of Delaware Application December 4, im, serai No. seam c claim. (ci. zei-4s) `This invention relates to a telemetric oil pressure indicating system and has particular reference to its application to the oil circulating system of the internal combustion engine of an automotive vehicle. The novelty of the invention resides in specific details of construction of an engine unit which is applied to the engine. 1n the unit there is positioned a diaphragm sub- `,tect to the pressure of the force feed 01.11118 BYB- tem of the engine. The movement of the diaphragm caused by the oil pressure moves a lever which causes acontact to move over a' resistance and to put more or less resistance in an electric circuit. A galvanometer in the circuit will indicste the amount of current passing through the circuit, and by graduating the dial of the galvanometer in pressures instead of electric units. the pressure in the oil circulating system may be read directly on the galvanometer dial.

On the drawing:

Figure l is a view of an internal combustion engine with the engine unit applied and showing the circuit of the telemetric system.v Y

Figure 2 is a sectional detail view through the engine unit of the engine.

Figures 3 and 4 are sectional detailed views on the corresponding lines of Figure 2.

Referring to the drawing, the numeral 2 indicates an internal combustion engine as a whole. The engine has the engine head 4,v the oil pan 5, and the clutch housing 8. At the top of the 'engine head 4 there is the casting I0 of the or mounted at one end of the oil manifold 24. From the engine unit 28 a wire Il leads to a galvanometer I2 which is usually mounted on the instrument panel of the vehicle. The usual battetryis indicated at 34 and the ground connection a Referringto Figure 2, the engine unit 25 comprises the base 2l which has the screw-threaded neck 28 at one end and the ared flat seat 4l at the other end. Intermediate the neck 28 and the seat 40, the base is quadrangular in shape as indicated at 42.

On the seat 40 at the periphery of the baseY placed the disc spring 48 the details of which ina casting l2 secured to the front of the engine 5 block. On the water pump shaft there is also mounted theu'sual fan I4 and both the fan and pump are driven by a belt I8 operated from a wheel Il secured on the exterior of the crankshaft to the engine.

' A suitable housing 20 at the side of the crankcase of-the engine houses the usual oil pump driven from-the crankshaft of the engine. A pipe 22 leads from the oil pan t tothe pump in vthe housing 20. The pump draws the oil from theoil pan and passes it to an oil manifold 24. From the oil manifold suitable ducts or pipes lead to the various parts to be lubricated.

The parts so far described are conventional. and per se form no part of the invention. y

The invention itself is concerned with the eneine lurm'. :t or the teiememc ou circulating sysare best disclosed in Figure 4. The spring has its center cut away and there are cut in the disc a plurality of radial slots 49 which form fingers 5l therebetween with the points of the ngers at the center of the disc spring. The slots 45 are equally spaced and the fingers 5i are of the same size. 'I'he spring constantly urges the diaphragm downwardly when considering the construction of Figure 2.

Over the disc spring 40 there is placed a relatively flat retainer element 5l. The edge of the element 50 is bent away from the main part and seats on the periphery of the disc spring 4B. Over the retaining element 50 there is positioned a mounting plate 52. The retaining member 50 and the plate 52 each has a central opening 54 therein, the purpose of which is to enable a stud 55 to project therethrough. The stud 56 has a relatively flat head 58 which rests on the fiat central part GII of the diaphragm and over which there are received the ends or tips of the iingers 5|.

The edge ofY the mounting plate 52 is bent around and overlaps the edges of the seat 40, the diaphragm 44, spring disc 4B, and retainer 50, as shown at 62 in Figure 2. This turned over part 52 of the mounting plate 52 rigidly holds the base, the diaphragm, the spring disc and the retainer 50 together. A fluid-tight connection is formed because the gasket 44 is compressed when part 62 is applied.

At one side of the mounting plate 52 a, tongue 64 is struck up therefrom and this tongue 54 fits into a'recess 66 formed in a. cap or housing 68 which fits over the base member and its associated parts. This cap or housing 68 4is secured to the base member by means of the turned over edge ll; A suitable gasket 'I2 is positioned between the shoulder I4 on theturned over part 'Il and adjacent the plate I! to form a fluid-tight connection. 'Ihe linger M and the recess l are for the Purpose of accurately positioning the housing on the remainder of the structure. y

The moimting plate l2 has ears 1I and 1l thereon formed by pressing metal away from the plane oi the mounting plate. Outside these ears there are received the legs Il and i2 oi' the U- shaped part Il oi a lever indicated es a whole at Il. 'lhe ears 1l and Il as well as the legs iii and l2 have mating openings in which there are received the Journals II and Il of a journal member 02. This member I! is formed into u-shape intermediate the journals Il and I as indicated by the numeral I4. The part I4 is held to the mounting plate l2 by the ends of a lug Il pressed from the plane o! the mounting plate il. 'I'he journals Il and Il serve pivotally to mount the lever I6.

A coil spring Ill is coiled about the journal Il and has one end thereof held to the leg Iii hy means o! a linger il! bent from the side oi the leg III. 'I'he other end |04 oi' the spring is held to the mounting plate 52 by means o( a lug or linger I formed from the plane of the mounting plate i2.

The lever It has an arm Ill formed as a continuation of the base of the U-shaped part Il. As is best shown in Figure 3, the arm l has a V shape where it joins onto the U-shaped part I4 and terminates in a goose-neck arm as is best shown in Figure 2. The end oi the arm has the spring III secured thereto by a rivet ||2 and the end of the spring Ill has secured thereto a contact Ill. 'I'he shape of the spring arm ill is best shown in Figure 3. This contact ||I is adapted to move over a wire resistance element III which is wound around a non-conducting strip Il! and is spaced from the top |20 of the housing by means of the insulating material |22.

'I'he resistance III has a' contact stud |24 se cured at one end. This stud passes through an opening in the top |20 of the housing Il. The stud has a head |20, spaced from the housing by the insulating member |28. An insulating washer III is positioned on the outside oi' the housing and a metal washer |3I and a nut |32 vhold the stud tightly on the housing and out oi electrical contact therewith.

Referring again to the lever Ii, and particularly to thebase oi the u-shaped part u, it will be seen that. the metal thereof is bent into U shape asindicated at |34.

itseli and is bent into a plane which is at an ineline to the plane of the remainder of the base oi the U-shaped part Il. This is best seen in Figure 2. Both legs of the U-shaped Dart |34 are provided with threaded openings III into which there is screwed the adjusting screw |33. The lower end of the adjusting screw is rounded and rests on the top ot the stud I6. By turning the screw |30 one way or the other, the unit may be calibrated so that the contact IM is at such a position on the resistance that the pointez P This U-shaped part I is merely formed by turning the metal on which in will swing the lever on its journals Il and Il thereby to cause the arm Ill to move -the contact Ill over the resistance III to place additional resistance in the circuit. Due to the increase in the resistance, the pointer P will now move from the zero end oi the scale. as shown in Figure l. to the other end to indicate the amount oi.' pressure in the oiling system.

Toadjustthepositionoithepointoithe screw |38 on top o! the st'ud N the lever Il can bebentinalldirectionsatthethinsectionoonnecting the lever to the U-ahaped part |34. This bending can take place at either side or both sides oi supporting Dart |34. After this adiustment is made to take care of the particular diaphragmandbackingspringusedintheunit,the screw i can be turned in one direction or the other to etlect calibration. The screw III is therefore capable of axial adjustment by turning it, and bodily adjustment angularly with respect to the diaphragm by bending or twisting the thin sections.

Suppose that the pointer is at the position on the scale which indicates the normal or desired oil pressure. Ii for any reason, such. as due to the lack of oil, or the failure of the oil pump, there will be a decrease in the pressure of the system, this decrease in the pressure will at once aect the position of the diaphragm The oi the galvanometer I2 will be at the zero posispring Il will cause the diaphragm to move toward the position shown in Figure 2. and as the diaphragm moves toward this position the spring I will move the lever to cause the contact ||4 to move toward the position it occupies in Figure 2. Thiswiilchangetheresistanceoitheengine unit in the circuit and cause the pointer P to move toward the zero position in Figure l and indicate the deilciency in pressure in the oil circulating system.

I claim:

1. In an engine unit oi' a telemetric indicating system, a base mountable on the engine, a diaphragm positioned on the base, said base having an opening to enable oil from the oil circulatingsystem oftheenginetoreachthediaphragm and exert pressure thereon. a spring biasing the diaphragm in opposition to the oil pressure,meanstohold thediaphragm andthe spring on the base. a housing mounted over and securedtothebase,aresistancemountedinthe housing and forming part of an electric circuit, a contact movable along the resistance. and means for eil'ecting relatively large movements of the contact along the resistance in response to movements of the diaphragm, said means including lever means for moving the contact, means extending between the diaphragm and the means to cause movement oi the means in response to movement oi the diaphragm. and a mounting for the last-named extending means providing for adjustment of said extending means to vary the effective distance between the diaphragm and the lever means and to vary the angular relation of said extending means with respect to the diaphragm.

2. In an engine unit of a telemetric indicating system, a base mountable on the engine. a diaphragm positioned on the base, said base having an opening to enable oil from the oil circulating system oi the engine to reach the diaphragm and exert pressure thereon, a disc spring positioned on the diaphragm to bias it in oppomtion to the oil pressure, a retainer positioned on the disc spring. a mounting plate positioned over the retainer and securing the base, the diaphragm,

the spring and the retainer together, a levervhaving a U-shaped part -the two legs-of which are pivotally mounted on said plate and an arm extending away from the U-shaped part, a housing mounted over the Alever and secured te the base, a resistance mounted in the housing and forming part of an electric circuit, a contact mounted on the arm and adapted to move over the resistance in response to movements of the lever. and an adjusting screw mounted in the bight of the U-shaped'part of the lever and extending axially between the two legs oi the U- shaped part and between the diaphragm and the lever to cause movement of the lever in kresponse to movement of the diaphragm.

3. In an engine unit of an electric telemetric oil pressure indicating system. a base mountable on the engine, a diaphragm mounted in the base, a lever pivoted on the unit, a contact mounted on the lever and adapted to move over a resistance element to change the amount of resistance in an electrical circuit, means extending from the lever to the diaphragm to cause movements of the diaphragm to be transmitted to the lever, said means including a member for varying the eiiective distance between the lever and the diaphragm. and supporting means for said member mounted on the unit for universal angular movement with respect to the diaphragm, whereby adjustment and calibration o! theunit may be eii'ected. i

4.Inanengine\mitofanelectrictelemetric oil pressure indicating-system. a base mountable on the engine, a diaphragm mounted in the base. a lever pivoted on the unit, a contact mounted on the-lever and-adapted to move -over a 'resistance element to change the amount of` resistanceinanelectricalcircinhascrewextenm' cause movements of the diaphragm to be transmitted to the lever, said screw being axially adjustable byturning it, and' supporting means for said screw twistably mounted on the unit tor universal angular movementlwith respect tothe diaphragm, whereby the unit may be adjusted and calibrated.

5. In an engine unit of an electric telemetric oil pressure indicating syste a base mountable on the engine, a diaphra mounted in the base, a lever pivoted on the unit, a contact mounted on the lever and adapted to move over a resistance element to change the amount of resistance in an electrical circuit, said lever having a supporting part and a relatively A'thin bendable part connecting the supporting part to the remainder of the lever. and adjustable means moimted on the supporting part of the lever andV extending between the diaphragm and lever t0 cause movements ci the diaphragm to be transmitted to the lever, whereby universal adjustment oisaid means andcalibration of the unit may beeiect'ed.

l 6. In an engine unit of an electric telemetric oil pressure-indicating system, a base mountable on the engine, a diaphragm mounted in vthe base, a lever pivoted onthe unit, a contact mounted on the leverand adapted to'move over a' resistance element to change the amountv of resistance in an electrical circuit, said lever having a supporting part and relatively thin bendable parts connecting the supportingpart tothe 1 remainder of the lever, and a-screw mounted on lnsfrmthelsvortowsrdwdhvhnsmtomeant so.; 2,2e6,717.'"

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said supporting part and extending between the diaphragm and lever te cause movements ot the diaphragm 'to be transmitted to the lever, whereby axial and bodily adjustments of the screw andv calibration oi the unit may be eii'ected.

BAGNAR CLASON.

l June 16,' 1914.2,v

It is hereby' certi-.ridad that error appears 1n printed specification "of the above rxmiinsred,"'patent-11'fequring correction as follows: Page 2, sec-l '911656115111' 115 58119-im l; before "means" both occurrences, 'insert thej" word -gil,'e'yrer`;l and blaat thev said Letters Patent should be read-with this correction therein that the samemay conform .tothe record of thecase in signed'snd sealed this lien day or August, LiL- 1912,

v Henrylan A rsdale, Acting Commissioner of Patents.

ycmu'new: or cnncwion,

Patnt 119.12,286,711." v "June 16,"19h2,

Hmm cmsom word '--v-sle'vez'j;l and that: the. said Letterp Patent should be read-.with this ".zcorrectin vtherein that-thesame. may conform .to 'the `reworl of ishal case 1n .the 'kunt ofn. 'Y -v V signedand sealed this um day o; August, A. i). -19Lp2. v

, Arsdle,

(S911) f l Acting Connasioner of Pat'ents.

the "kunt office;

" sigma-and sealed unis-mi day 01j Augustb'fh. i). :191;2,

(onlyA l L 'Ac'ting commissioneror Pmiernz.V 

